Justice Anthony M. Kennedy, announcing the court’s decision Monday, wrote that the “imperative to purge racial prejudice from the administration of justice” requires setting aside the traditional rule that bars judges from second-guessing what went on in the jury room.

The 5-3 decision announced a limited exception to that rule against second-guessing juries. The new rule covers cases in which “one or more jurors made statements exhibiting overt racial bias that cast serious doubt on the fairness and impartiality of the jury’s deliberations and resulting verdict.”

Kennedy did not say exactly what should happen in such cases, other than that the trial judge should look into the matter, question the former jurors and then decide whether a new trial is called for.

Kennedy also added that racial bias is “a familiar and recurring evil that, if left unaddressed, would risk systemic injury to the administration of justice,” reports NPR.